Early in his career, Heath Ledger fretted about being typecast as a young blond heartthrob. He played one on TV in his native Australia, and he made his Hollywood movie debut in 1999 as a cheeky Aussie hunk in 10 Things I Hate About You, a teen-friendly variation on The Taming of the Shrew. But Ledger wanted to do more, and go deeper.

Six years later, he showed just how deep he could go. In his career-high performance as Ennis Del Mar in Brokeback Mountain, the alluringly restless actor with the wary, old eyes seemed to have skinned everything extraneous from the shape of the conflicted man he played. His Ennis moved economically, with a minimum of talk that masked a maximum of hunger. Speaking in a mumbled Western drawl from way back in his throat, the bloke born in Perth, Western Australia, busted out of all conventions to play a Wyoming herder, a husband to a bewildered wife, a father, and a man sideswiped by the love and lust he felt for another man.

Ledger always had that coiled intensity in him — just watch him in The Patriot (2000). He was so eager to distance himself from cutie-boy roles that he readily hoisted a musket, fought the British redcoats, and accepted Mel Gibson as his father. In A Knight's Tale (2001), Ledger was under pressure to deliver his first big Hollywood role — often a mixed blessing for young actors — and he managed to charm, even if it meant flirting once more with his Tiger Beat cred as a medieval serf-turned-bitchin’ knight. By Ned Kelly (2003), about the 19th-century Australian outlaw, the actor had begun to more confidently explore the real dark side of male lawlessness. This was an actor, not just somebody playing dress-up.

I happened to love Ledger in the hastily dismissed Casanova (2005), largely because of his wit in the title role. And while I loathed the glam-grubbiness of the addict pic Candy (2006), I couldn’t take my eyes off him for the abandon with which he inhabited such sickly skin. For now we can savor a fully engaged Ledger who vanishes into one of the six imagined ”Bob Dylans” in Todd Haynes’ adventurous biopic I’m Not There. The achievement, and the movie title, are all the more poignant for what they tease of future excellence, interrupted.